The proposed research program will continue to focus on the abnormalities of glucose and lipid metabolism in the adipocyte associated with obesity. Emphasis will be directed towards elucidating the cellular mechanism(s) responsible for these metabolic alterations. In this phase of the program, glucose transport activity by adipose cells, both in the absence and presence of insulin, will be examined in detail and related to simultaneous determination of the character of glucose metabolism and insulin binding by these cells. An attempt will be made to assess the influence of both adiposity and diet on these cellular functions through conducting experiments in nonobese and obese animals ingesting diets of differing caloric content and composition. Various models of animal obesity, including the Zucker fatty and aging rat, will be studied.